Engine Mechanical – V6 Page 6A1–33
2.9 Upper Engine Noise, Regardless of
Engine Speed
NOTE
A cold piston knock, which disappears in
approximately 1.5 minutes from start up, should
be considered acceptable. A cold engine knock
usually disappears when the specific cylinder’s
secondary ignition circuit is grounded out during
diagnosis.
A light rattle/tapping noise may indicate a valve train/upper engine concern, while a low rumble/knocking may indicate a
crankshaft, piston or lower engine concern.
Cause Correction
Low oil pressure. 1 Perform an oil pressure test, refer to 2.19
Engine Oil Pressure Diagnosis.
2 Repair or replace the engine oil pump as required, refer to 3.17 Oil Pump Assembly.
W orn or loose stationary hydraulic lash adjusters (SHLA)
and/or valve rocker arms.
The SHLAs, rocker arm and roller bearings should be intact
and in the correct position. 1 Clean, inspect and replace the camshaft lash
adjusters as required, refer to 3.21 Stationary
Hydraulic Lash Adjuster.
2 Replace the SHLAs and/or rocker arms as required, refer to 3.21 Stationary Hydraulic Lash Adjuster or
3.20 Rocker Arm.
Incorrect lubrication to the stationary hydraulic lash
adjusters and valve rocker arm. Inspect the following components and repair or replace as
required:
• valve rocker arms, refer to 3.20 Rocker Arm.
• stationary hydraulic lash adjusters, refer to 3.21
Stationary Hydraulic Lash Adjuster.
• oil filter by-pass valve, refer to 3.3 Oil Filter
Adaptor.
• oil pump and suction pipe, refer to 3.17 Oil Pump
Assembly.
• cylinder head oil galleries, refer to 3.22 Cylinder Head
Assembly.
• cylinder block oil galleries, refer to 4.7 Cylinder
Block.
Broken Valve Spring. Replace the valve spring, refer to 3.22 Cylinder Head
Assembly.
Stretched or broken timing chain/s and/or damaged timing
chain sprocket teeth. Replace the timing chains or sprockets as required, refer to
3.16 Timing Chains, Tensioners, Shoes and Guides.
W orn or faulty timing chain tensioner or guide. Replace the timing chains or sprockets as required, refer to
3.16 Timing Chains, Tensioners, Shoes and Guides.
W orn camshaft lobes. Replace the camshaft/s and SHLAs as required, refer to
3.19 Camshaft or 3.21 Stationary Hydraulic Lash
Adjuster.
W orn valve guides and/or valve stems. Inspect and repair or replace valves and valve guides as
required, refer to 3.22 Cylinder Head Assembly.
Stuck valves.
Carbon on the valve stem or valve seat may cause the
valve to stay open. Inspect and repair or replace valves and valve guides as
required, refer to 3.22 Cylinder Head Assembly.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–34
2.10 Lower Engine Noise, Regardless of
Engine Speed
NOTE
A cold piston knock which disappears in
approximately 1.5 minutes from start up should
be considered acceptable. A cold engine knock
usually disappears when the specific cylinder’s
secondary ignition circuit is grounded out during
diagnosis.
A light rattle/tapping noise may indicate a valve train/upper engine concern, while a low rumble/knocking may indicate a
crankshaft, piston or lower engine concern.
Cause Correction
Low oil pressure. 1 Perform an oil pressure test, refer to 2.19
Engine Oil Pressure Diagnosis.
2 Repair or replace the engine oil pump as required, refer to 3.17 Oil Pump Assembly.
W orn accessory drive components.
Abnormalities such as severe cracking, bumps, stretching
or missing areas on an accessory drive belt and/or
misalignment of accessory drive system components. Inspect the accessory drive system, repair or replace
components as required, refer to 3.5 Accessory
Drive Belt.
Loose or damaged crankshaft balancer and pulley
assembly. Repair or replace the crankshaft balancer and pulley
assembly as required, refer to 3.13 Crankshaft Balancer
Assembly.
Detonation or spark knock. Confirm the correct operation of the ignition system, refer to
6C1-2 Engine Management – V6 – Diagnostics.
Loose torque converter bolts. Inspect and tighten the torque converter bolts to the correct
torque specification, refer to 7C4 Automatic Transmission –
4L60E – On-vehicle Servicing.
Loose or damaged flexplate. Repair or replace the flexplate as required, refer to 4.3
Flexplate Assembly.
Oil pump suction pipe loose, damaged or restricted. Clean, inspect and repair/replace the oil pump suction pipe as required, refer to 4.2 Oil Pan and Oil Pump Suction
Pipe Assembly.
Excessive piston-to-cylinder bore clearance. Inspect the piston and cylinder bore and repair/replace
components as required, refer to 4.5 Pistons, Pins,
Rings, Connecting Rods and Big-end Bearings and 4.7
Cylinder Block.
Excessive connecting rod bearing clearance. Inspect the connecting rod, crankshaft and bearings and
repair/replace components as required, refer to 4.5
Pistons, Pins, Rings, Connecting Rods and Big-
end Bearings and 4.6 Crankshaft and Main Bearings.
Excessive piston pin to bore clearance. Inspect the pistons and pins and repair/replace components
as required, refer to 4.5 Pistons, Pins, Rings,
Connecting Rods and Big-end Bearings.
Excessive crankshaft main bearing clearance. Inspect the crankshaft, cylinder block journals, main
bearings and main bearing caps and repair/replace
components as required, refer to 4.6 Crankshaft
and Main Bearings and 4.7Cylinder Block.
Incorrect piston, pin and connecting rod installation.
Pistons must be installed with the mark or dimple facing the
front of the engine. Piston pins must be centred in the
piston pin bore. Confirm the pistons, pins and connecting rods are installed
correctly and repair if required, refer to 4.5 Pistons, Pins,
Rings, Connecting Rods and Big-end Bearings.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–35
2.11 Engine Noise Under Load
NOTE
A cold piston knock which disappears in
approximately 1.5 minutes from start up, should
be considered acceptable. A cold engine knock
usually disappears when the specific cylinder’s
secondary ignition circuit is grounded out during
diagnosis.
A light rattle/tapping noise may indicate a valve train/upper engine concern, while a low rumble/knocking may indicate a
crankshaft, piston or lower engine concern.
Cause Correction
Low oil pressure. 1 Perform an oil pressure test, refer to 2.19
Engine Oil Pressure Diagnosis.
2 Repair or replace the engine oil pump as required, refer to 3.17 Oil Pump Assembly.
Detonation or spark knock. Confirm the correct operation of the ignition system, refer to
6C1-2 Engine Management – V6 – Diagnostics.
Loose torque converter bolts. Inspect and tighten the torque converter bolts to the correct
torque specification, refer to 7C1 Automatic – 4L60E –
General Information – 4L60E – General Information.
Cracked flexplate. Replace the flywheel/flex-plate as required, refer to 4.3
Flexplate Assembly.
Excessive connecting rod bearing clearance. Inspect the connecting rod, crankshaft and bearings and
repair/replace components as required, refer to 4.5
Pistons, Pins, Rings, Connecting Rods and Big-
end Bearings and 4.6 Crankshaft and Main Bearings.
Excessive crankshaft bearing clearance Inspect the crankshaft, cylinder block journals, main
bearings and main bearing caps and repair/replace
components as required, refer to 4.6 Crankshaft
and Main Bearings and 4.7Cylinder Block.
2.12 Engine Will Not Crank – Crankshaft Will Not Rotate
Cause Correction
Seized accessory drive system component. 1 Remove the accessory drive belt, refer to 3.5
Accessory Drive Belt.
2 Rotate the crankshaft by hand at the balancer pulley or flywheel.
3 Repair or replace accessory drive system components as required.
Hydraulically locked cylinder caused by:
• coolant in cylinder,
• oil in cylinder, or
• fuel in cylinder. 1 Remove the spark plugs and check for fluid, refer to
6C1-3 Engine Management – V6 – Service
Operations.
2 Inspect for broken head gasket/s.
3 Inspect for cracked engine block or cylinder head.
4 Inspect for sticking fuel injector.
5 Repair or replace components as required.
Seized torque converter. 1 Remove the torque converter bolts, refer to 7C1
Automatic – 4L60E – General Information – 4L60E –
General Information.
2 Rotate the crankshaft by hand at the balancer pulley or flywheel.
3 Repair or replace torque converter as required.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–40
Cause Correction
W orn valve guides and or valve stems. Inspect and repair valves and valve guides as required,
refer to 3.22 Cylinder Head Assembly.
W orn or damaged valve stem oil seal. Replace valve stem oil seals as required, refer to 3.22
Cylinder Head Assembly.
Piston rings broken, worn or not seated correctly. Allowing adequate time for the piston rings to seat correctly,
replace piston rings as required, refer to 4.5 Pistons, Pins,
Rings, Connecting Rods and Big-end Bearings.
Piston rings incorrectly installed or not matched to cylinder
bore oversize. Replace piston rings as required, refer to 4.5 Pistons, Pins,
Rings, Connecting Rods and Big-end Bearings.
2.18 Engine Oil Leak Diagnosis
Introduction
It is important to correctly identify the source of an engine oil leak. For example, a power steering fluid leak or spillage
during servicing can travel across the valley area of the engine and run-out the weep hole, which is located at the back of
the cylinder block. Failure to correctly identify the source of an engine oil leak can lead to unnecessary replacement of
engine components.
Most fluid leaks can be repaired by repairing or replacing the faulty component or resealing the gasket surface. However,
once a leak is identified it is important to determine and repair the cause as well as the leak itself.
Locating and Identifying the Leak
Inspect the leaking fluid and determine whether it is engine oil, transmission fluid, power steering fluid, brake fluid or
some other fluid. If unsure of the source of the leaking lubricant, a quick check of fluid levels should indicate where the
fluid is coming from, as one or more fluid level should be low.
Visual Inspection
Once the type of leaking fluid has been determined, a visual inspection of the affected system should be performed.
W hen performing the visual inspection:
1 Bring the vehicle to the normal operating temperature.
2 Park the vehicle over a large sheet of paper or other clean surface.
3 Leave the vehicle idling for 2-3 minutes, then check for dripping fluid.
4 If required, identify the type of fluid leaking and the approximate location of the leak.
5 Visually inspect the suspected area. A small mirror may assist viewing areas that are difficult to see normally.
6 Check for leaks at all sealing surfaces and fittings.
7 Check for any cracked or damaged components.
8 If the leak cannot be located, completely clean the entire engine and surrounding components, drive the vehicle at normal operating temperature for several kilometres and then repeat Steps 3 to 8.
9 If the leak still cannot be located, proceed with either the Powder Method or Black Light and Dye Method as outlined below.
Powder Method
1 Completely clean the entire engine and surrounding components.
2 Apply an aerosol type powder (e.g. foot powder) to the suspected area.
3 Operate the vehicle at normal operating temperature and at varying speeds for several kilometres.
4 Identify the source of the leak from the discoloration of the powder around the suspect components.
5 If required, use a small mirror to assist in viewing areas that are difficult to see normally.
6 Refer to Possible Causes for Engine Oil Leaks in this Section, and repair or replace components as required.
Black Light and Dye Method
A black light and die kit Tool No. J28428-E or a commercially available equivalent is available to technicians to aid in
engine oil leak diagnosis. W hen using a black light and die kit for the first time, it is recommended the technician read the
manufacturers instructions prior to using the kit.
1 Add the specified amount of dye, as per manufacturers instructions, into the engine or suspected source of the oil leak.
2 Operate the vehicle at normal operating temperature and at varying speeds for several kilometres.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–41
3 W ith the vehicle parked on a flat level surface, aim the black light at the suspected component/s. The dyed fluid will
appear as a yellow path leading to the oil leak source
4 Refer to Possible Causes for Engine Oil Leaks in this Section, and repair or replace components as required.
Possible Causes for Engine Oil Leaks
Common possible causes for engine oil leaks are:
• higher than recommended fluid levels,
• higher than recommended fluid pressures,
• blocked or faulty fluid filters or pressure relief valve,
• blocked or faulty engine ventilation system,
• incorrectly tightened or damaged fasteners,
• cracked or porous components,
• incorrect gaskets or sealants used,
• incorrect gaskets or sealant installation,
• damaged or worn gaskets or seals, and
• damaged or worn sealing surfaces.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–54
3.1 Engine Oil
The procedure outlined below is typically the same for both rear wheel drive and all wheel drive vehicles.
Check
The following procedure is applicable to both rear wheel and all wheel drive vehicles
1 Run the engine to bring it to normal operating temperature.
2 Park the vehicle on a level surface. A vehicle that is not level will affect the accuracy of the level reading.
3 Stop the engine and wait 5 to 10 minutes to allow the oil to drain back into the oil pan.
4 Remove the oil level indicator (1) and wipe clean.
5 Insert the indicator, ensuring it is fully seated.
6 Slowly remove the indicator to avoid smearing. Hold it horizontally or with lower end slightly down to avoid
oil running along indicator.
7 Observe the oil level where it passes over the centre line of the indicator.
8 If the level is lower than the Add mark (2), add enough oil to the engine to reach the Upper mark (3).
Do not add too much oil as the reading should never
be above the Upper mark.
NOTE
When topping up the oil, allow approximately 5
to 10 minutes for the added oil to fully drain into
the oil pan.
Figure 6A1 – 23
Replace
NOTE
• Quicker and more complete draining will
occur if the engine oil is at normal operating
temperature. However, care must be taken to
avoid scalding from the hot oil.
• It recommended the oil filter be changed at
each engine oil change, refer to 3.2 Oil
Filter.
1 Remove the oil fill cap.
2 To ensure complete draining of the oil pan, raise the front and rear of the vehicle to maintain a level attitude. If not using a hoist, support the vehicle with safety stands, refer to 0A General Information.
3 Clean any foreign material from around the oil drain plug and place a suitable, clean drain tray under the engine.
The oil may be hot. Avoid contact with the oil.
Ensure that eyes and skin are protected.
4 Remove the drain plug (1), taking care to avoid scalding from the hot oil. Allow the oil to drain.
5 Clean and inspect the drain plug threads. If damaged, replace the drain plug.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–77
12 Remove the three bolts (1), attaching the exhaust
manifold inner heat shield to the exhaust manifold.
13 Using a suitable commercially available non-corrosive cleaning solvent and a soft bristled parts cleaning
brush, thoroughly clean the exhaust manifold.
14 Dry the exhaust manifold using compressed air.
Safety glasses must be worn when using
compressed air.
Figure 6A1 – 59
NOTE
• The same procedure applies to the Right-
hand exhaust manifold.
• To gain access to the lower rear exhaust
manifold attaching bolts (2), apply a slight
downward movement to the coolant inlet
pipe (1).
Inspect
Inspect the exhaust manifold (1) for the following:
• Damage to the threaded holes for the heat shield
mounting.
• Damage to the exhaust manifold mounting holes.
• Damage to the threads of the exhaust manifold to
exhaust pipe flange studs.
• Damage to the gasket sealing surfaces.
• Using a straight edge (2) and feeler gauges (3), check
the cylinder head mounting face of the exhaust
manifold does not exceed the maximum distortion
specification of 0.25mm.
NOTE
If the surface flatness is not within
specifications, the exhaust manifold is warped
and must be replaced.
Figure 6A1 – 60
Reinstall
Reinstallation of the exhaust manifold assembly is the reverse of the removal procedure, noting the following:
1 Ensure the exhaust manifold, cylinder head and exhaust pipe flange surfaces are clean.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–163
12 Remove and discard the cylinder head gasket (1).
Figure 6A1 – 278
Disassemble
1 Using an appropriately sized deep socket (1) and a plastic hammer (2), lightly tap on the valve spring
retainer to loosen the valve collets.
CAUTION
Ensure valve heads will not contact anything
during this step in order to avoid bending or
damage.
Figure 6A1 – 279
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